This invention relates generally to seating systems, for example for wheelchairs. The invention may also have application to other seating systems that call for a person using a seat to be provided with precise postural control during conditions that may hamper stability of seated position. Examples of such applications are seating systems for heavy equipment, such as logging or earth-moving equipment or for surgeons carrying out specialized types of surgery.
Broadly speaking, the invention seeks to address postural support problems for people of all ages. However, the invention has been devised primarily in the context of pediatric seating systems for wheelchairs. So-called xe2x80x9cadaptivexe2x80x9d seating systems play an important role in the lives of many children with physical disabilities. These systems help keep children comfortable and secure while they are in their wheelchairs. Seating systems make it easier for them to breathe, eat and communicate. In North America, it is estimated that about 40,000 children between the ages of five and twelve have moderate-to-severe seating problems and need special wheelchair seating systems.
Finding an appropriate wheelchair seating system for elementary school-age children with positioning problems is challenging for families. Modular, xe2x80x9cout-of-the-boxxe2x80x9d wheelchair seats often do not provide sufficient adjustment to position many children with disabilities. Alternatively, custom wheelchair seats can be designed, constructed and fit so children get the support they need for everyday activities. However, custom seating systems are expensive, require specialized seating teams to produce them, and are difficult to adapt for daily activities and growth.
The present invention provides a seating system which includes at least seat and back components that are adjustable to provide individualized posture control for a person using the seating system. Preferably, the seating system includes first, second and third pelvic stabilization components, namely:
(1) a raised barrier that extends transversely of the seat at a distance spaced forwardly of a rear end of the seat for co-operating with the ischial tuberosities of the pelvis to control rotation of the pelvis beneath the person;
(2) a pad extending transversely of the back at a location to provide resistance to the posterior superior iliac spine (PSIS) of the pelvis; and,
(3) means extending transversely of and spaced above the seat in the vicinity of the upper thigh area of the person, for controlling anterior and rotational movement of the pelvis.
In summary, it has been discovered that precise upper body control may be achieved by providing a seating system that has the three pelvic stabilization components referred to previously, for co-operating with, respectively, the ischial tuberosities, the PSIS, and the frontal pelvic area of the person. In practice, the latter component may comprise one or more pads that are in the vicinity of the upper thighs (as well underlying muscle tissue and sinew), beneath the anterior superior iliac spine (ASIS) of the pelvis. In this context, it is understood that the superior iliac spine continues around the top, front and back of the pelvis and provides anterior and posterior stabilization areas for the pads.
The description which follows includes additional features of the seating system of the invention that may be used together or individually, in combination with the three pelvic stabilization components identified previously.
As noted above, the invention has been devised primarily in the context of paediatric seating systems for wheelchairs. Accordingly, the description and the accompanying drawings refer to this particular application of the invention by way of example and without limitation. The acronym MPS is used to refer to the inventive xe2x80x9cModular Paediatric Seatingxe2x80x9d system.